Parabolic reflector array signal processing for improved rural area coverage in personal satellite communications

This paper describes and analyzes a method for improving wide-area coverage for hand-held portables by employing on-board digital beamforming satellite in geostationary orbit. The proposed approach to coverage optimization involves on-board array signal processing of multiple feeds in a parabolic reflector antenna. Code division multiple access (CDMA) signalling provides an estimate of each mobile's steering vector. A new single-beam-per-user beamforming network is described. Results indicate that the system is able to provide nearly uniform Canadian coverage using only a five-element antenna array. It is shown that link margins are typically increased from a minimum required 5.25 dB to around 7.5 dB in border areas compared to a conventional isolated beam system.